Plating device

ABSTRACT

A plating apparatus according to the present invention has a plating tank ( 40 ) for holding a plating solution ( 10 ), an anode ( 56 ) disposed so as to be immersed in the plating solution ( 10 ) in the plating tank ( 40 ), a regulation plate ( 60 ) disposed between the anode ( 56 ) and a plating workpiece (W) disposed so as to face the anode ( 56 ), and a plating power supply ( 24 ) for supply a current between the anode ( 56 ) and the plating workpiece (W) to carry out plating. The regulation plate ( 60 ) is disposed so as to separate the plating solution ( 10 ) held in the plating tank ( 40 ) into a plating solution on the anode side and a plating solution on the plating workpiece side, and a through-hole group ( 68 ) having a large number of through-holes ( 66 ) is formed in the regulation plate ( 60 ).

TECHNICAL FIELD

[0001] The present invention relates to a plating apparatus for carryingout plating of a surface of a plating workpiece to be plated, such as asubstrate, and more particularly to a plating apparatus for forming aplated film in fine interconnect trenches or holes, via holes,through-holes, or resist openings formed in a surface of a semiconductorwafer or the like, or for forming a bump (protruding electrode), whichprovides electrical connection with an electrode of a package or thelike, on a surface of a semiconductor wafer.

BACKGROUND ART

[0002] In TAB (Tape Automated Bonding) or FC (Flip Chip), for example,it has widely been practiced to form protruding connecting electrodes(bumps) of gold, copper, solder, lead-free solder, or nickel, or amulti-layer laminate of these metals at predetermined portions(electrodes) on a surface of a semiconductor chip having interconnectsformed therein, and to electrically connect the interconnects via thebumps with electrodes of a package or with TAB electrodes. Methods offorming bumps include various methods, such as electroplating, vapordeposition, printing, and ball bumping. With a recent increase in thenumber of I/O in a semiconductor chip and a trend toward finer pitches,electroplating has more frequently been employed because it can copewith fine processing and has relatively stable performance.

[0003] With an electroplating method, a metal film (plated film) havinga high purity can readily be obtained. Further, an electroplating methodhas a relatively high deposition rate of a metal film, and control ofthickness of the metal film can be performed relatively easily.

[0004]FIG. 37 shows an example of a conventional plating apparatus whichemploys a so-called face-down method. The plating apparatus has anupwardly opened plating tank 12 for holding a plating solution 10therein and a vertically movable substrate holder 14 for detachablyholding a substrate W in a state such that a front face (surface to beplated) of the substrate W faces downward (face-down). An anode 16 isdisposed horizontally at a bottom of the plating tank 12. Overflow tanks18 are provided around an upper portion of the plating tank 12. Further,a plating solution supply nozzle 20 is connected to the bottom of theplating tank 12.

[0005] In operation, a substrate W held horizontally by the substrateholder 14 is located at a position such as to close an opening at anupper end of the plating tank 12. In this state, the plating solution 10is supplied from the plating solution supply nozzle 20 into the platingsolution tank 12 and allowed to overflow the upper portion of theplating tank 12, thereby bringing the plating solution 10 into contactwith a surface of the substrate W held by the substrate holder 14.Simultaneously, the anode 16 is connected via a conductor 22 a to ananode of a plating power supply 24, and the substrate W is connected viaa conductor 22 b to a cathode of the plating power supply 24. Thus, dueto a potential difference between the substrate W and the anode 16,metal ions in the plating solution 10 receive electrons from the surfaceof the substrate W, so that metal is deposited on the surface of thesubstrate W so as to form a metal film.

[0006] According to the plating apparatus, uniformity of the thicknessof the metal film formed on the surface of the substrate W can beadjusted to a certain extent by adjusting the size of the anode 16, aninterpolar distance and potential difference between the anode 16 andthe substrate W, a supply rate of the plating solution 10 supplied fromthe plating solution supply nozzle 20, and the like.

[0007]FIG. 38 shows an example of a conventional plating apparatus whichemploys a so-called dipping method. The plating apparatus has a platingtank 12 a for holding a plating solution 12 a therein and a verticallymovable substrate holder 14 a for detachably holding a substrate W in astate such that a front face (surface to be plated) is exposed while aperipheral portion of the substrate W is water-tightly sealed. An anode16 a is held by an anode holder 26 and disposed vertically within theplating tank 12. Further, a regulation plate 28 made of a dielectricmaterial having a central hole 28 a is disposed in the plating tank 12so as to be positioned between the anode 16 a and the substrate W whenthe substrate W held by the substrate holder 14 a is disposed at aposition facing the anode 16 a.

[0008] In operation, the anode 16 a, the substrate W, and the regulationplate 28 are immersed in the plating solution in the plating tank 12 a.Simultaneously, the anode 16 a is connected via a conductor 22 a to ananode of a plating power supply 24, and the substrate W is connected viaa conductor 22 b to a cathode of the plating power supply 24.Accordingly, metal is deposited onto the surface of the substrate W soas to form a metal film in the same manner as described above.

[0009] According to the plating apparatus, distribution of thickness ofthe metal film formed on the surface of the substrate W can be adjustedto a certain extent by disposing the regulation plate 28 having thecentral hole 28 a between the anode 16 a and the substrate W disposed ata position facing the anode 16 a, and adjusting a potential distributionon the plating bath 12 a with the regulation plate 28.

[0010]FIG. 39 shows another example of a conventional plating apparatuswhich employs a so-called dipping method. The plating apparatus differsfrom the apparatus shown in FIG. 38 in that a ring-shaped dummy cathode(dummy electrode) 30 is provided instead of a regulation plate, that asubstrate W is held by a substrate holder 14 a in a state such that thedummy cathode 30 is disposed around the substrate W, and that the dummycathode 30 is connected to a cathode of a plating power supply 24 duringplating.

[0011] According to the plating apparatus, uniformity of thickness of aplated film formed on the surface of the substrate W can be improved byadjusting an electric potential of the dummy cathode 30.

[0012] On the other hand, for example, when a metal film (plated film)for interconnects or bumps is formed on a surface of a semiconductorsubstrate (wafer), the metal film formed is required to be uniform insurface profile and in film thickness over the entire surface of thesubstrate. There are increasing demands for a high degree of uniformityin recent high-density packaging technologies such as SOC and WL-CSP.However, with the above conventional plating apparatuses, it is quitedifficult to form a metal film that meets a high degree of uniformityrequirement.

[0013] Specifically, when a substrate is plated by the plating apparatusshown in FIG. 37, a metal film is formed under a strong influence of aflow of the plating solution. If the plating solution flows fast, asshown in FIG. 40A, the thickness of the metal film P tends to be thickerin a central portion of the substrate W, to which metal ions aresufficiently supplied, than in a peripheral portion of the substrate W.If the flow of the plating the solution is made considerably weak inorder to prevent the above phenomenon, as shown in FIG. 40B, thethickness of the metal film P tends to be thicker in a peripheralportion of the substrate W than in a central portion. When a substrate Wis plated by the plating apparatus shown in FIG. 38, a potentialdistribution can be improved by the regulation plate having the centralhole, so that the uniformity of the film thickness distribution of ametal film can be improved to a certain extent over the entire surfaceof the substrate. However, as shown in FIG. 40C, the metal film P tendsto have an undulate thickness distribution, in which the film thicknessis thicker in a central portion and a peripheral portion of thesubstrate W. Further, when a substrate is plated by the platingapparatus shown in FIG. 39, it is difficult to adjust a voltage appliedto the dummy electrode (dummy cathode). In addition, it becomesnecessary to remove a metal film attached to a surface of the dummyelectrode, and the removal necessitates a troublesome operation.

[0014] In the conventional plating apparatuses, there is a generaltendency that due to a surface potential distribution produced over asurface of a substrate, the film thickness of a plated film is larger ina peripheral portion of the substrate, which serves as an electricallyreceiving portion, causing a U-shaped film thickness distribution overthe substrate surface (see FIG. 40B). This is one of the main factorsthat impair the uniformity of film thickness. In order to suppress thisphenomenon, a regulation plate or a dummy electrode is employed in amethod of regulating supply of metal ions to a surface of a substrate,i.e. regulating a flow of a plating solution, and a method ofcontrolling or regulating a potential distribution on a surface of asubstrate and an electric field in a plating tank.

[0015] The regulating method of a flow of a plating solution and theregulating method using a regulation plate are intended to concentratemetal ions or an electric field to a central portion of a substrate toraise a plated film at the central portion of the substrate, therebyadjusting a film thickness distribution of the plated film over theentire substrate surface so as to be a W-shaped distribution andminimizing a film thickness variation from an average film thickness(see FIG. 40C). Accordingly, the uniformity of the film thickness isgreatly influenced by regulation of the flow of the plating solution andby selection and fine control of the position of the regulation plateand the size of the central hole. Thus, the uniformity of the filmthickness is greatly influenced by the degree of adjustment (tuning).

[0016] On the other hand, the method using a dummy electrode is intendedto broaden a range of a potential distribution from a substrate surfaceto a region including the dummy electrode around the substrate, therebyshifting the raised portion of the plated film in the electricallyreceiving portion to the dummy electrode and obtaining an extremelyuniform film thickness on the substrate surface. As an equivalent methodto the method employing a dummy electrode, there has also been known amethod which uses a pattern in a peripheral portion of a substrate as a“discarded chip” so as to serve as a dummy electrode. In such methodsthat employ a dummy electrode, the uniformity of the film thickness isinfluenced by adjustment of a voltage. Further, it is necessary toperiodically remove a metal film (plated film) attached to the dummyelectrode, which necessitates a troublesome operation. When a pattern ina peripheral portion of a substrate is used as a “discarded chip” so asto serve as a dummy electrode, the number of effective chips persubstrate is inevitably reduced to thereby cause a lowered productivity.

[0017] All of the above-described methods eventually adjust a filmthickness distribution to obtain a uniform film thickness distribution.Thus, none of the above-described methods are intended to positivelycontrol or regulate an electric field in a plating tank, which isproduced between an anode and a plating workpiece as a cathode, so as tocontrol and improve a potential distribution on a surface of the platingworkpiece, thereby equalizing and improving the film thicknessdistribution of the plated film which would otherwise become a U-shapeddistribution.

DISCLOSURE OF INVENTION

[0018] The present invention has been made in view of the abovedrawback. It is, therefore, an object of the present invention toprovide a plating apparatus which can form a metal film (plated film)having a uniform thickness over an entire plating workpiece with arelatively simple arrangement and without needs for a complicatedoperation and setting.

[0019] In order to achieve the above object, the present inventionprovides a plating apparatus characterized by comprising a plating tankfor holding a plating solution; an anode disposed so as to be immersedin the plating solution in the plating tank; a regulation plate disposedbetween the anode and a plating workpiece disposed so as to face theanode; and a plating power supply for supply a current between the anodeand the plating workpiece to carry out plating, wherein the regulationplate is disposed so as to separate the plating solution held in theplating tank into a plating solution on the anode side and a platingsolution on the plating workpiece side, and a through-hole group havinga large number of through-holes is formed in the regulation plate.

[0020] According to the present invention, an electric field leaksthrough a large number of through-holes formed in the regulation platedisposed in the plating tank, and the leaked electric field spreadsuniformly. Accordingly, a potential distribution can be made moreuniform over an entire surface of the plating workpiece, and a withinwafer uniformity of a metal film formed on the surface of the platingworkpiece can be enhanced. Further, the plating solution is preventedfrom passing through a large number of through-holes formed in theregulation plate provided in the plating tank. Accordingly, non-uniformfilm thickness is prevented from being caused to a metal film formed onthe surface of the plating workpiece due to influence of a flow of theplating solution.

[0021] According to a preferred aspect of the present invention, thethrough-hole group is formed by a plurality of slit-like elongated holesextending linearly in one direction or extending in an arc. The use ofslit-like elongated holes as the through-holes can promote leakage ofelectric field while preventing the plating solution from passingthrough the through-holes. For example, the widths of the elongatedholes are set to be about 0.5 to 20 mm, preferably about 1 to 15 mm. Thelengths of the elongated holes are determined depending upon the shapeof the plating workpiece.

[0022] According to a preferred aspect of the present invention, thethrough-hole group is formed by a plurality of cross holes extendingcrosswise in vertical and horizontal directions.

[0023] According to a preferred aspect of the present invention, thethrough-hole group is formed by a combination of a plurality of fineholes, a plurality of holes having different diameters, and slit-likeelongated holes. The use of a combination of a plurality of fine holes,a plurality of holes having different diameters, and slit-like elongatedholes as the through-hole group can increase the productivity. Forexample, the diameters of the fine holes or small holes (peripheralholes) are set to be about 1 to 20 mm, preferably about 2 to 10 mm. Forexample, the diameters of large holes (central holes) are set to beabout 50 to 300 mm, preferably about 30 to 100 mm.

[0024] It is desirable that the through-hole group be formed in theregulation plate substantially over an entire area facing the platingworkpiece, and formed in an area substantially similar to a shape of theplating workpiece. With such a through-hole group, it is possible toform a metal film having a good film thickness uniformity in alldirections on the plating workpiece.

[0025] Preferably, the plating apparatus comprises an agitatingmechanism provided between the plating workpiece and the regulationplate for stirring the plating solution held in the plating tank. Byagitating the plating solution between the plating workpiece and theregulation plate by the agitating mechanism during plating, sufficientions can be supplied more uniformly to the plating workpiece. Therefore,a metal film having a more uniform thickness can be formed more rapidly.

[0026] Preferably, the agitating mechanism should comprise a paddle-typeagitating mechanism having a paddle which reciprocates parallel to theplating workpiece. By reciprocating a paddle parallel to the platingworkpiece during plating to agitate the plating solution by the paddle,the directionality of the flow of the plating solution can beeliminated, and simultaneously sufficient ions can be supplied moreuniformly to the surface of the plating workpiece.

[0027] According to a preferred aspect of the present invention, theanode and the regulation plate are provided in a vertical direction.This arrangement provides a plating apparatus with a small installationspace and having excellent maintainability.

[0028] The present invention also provides another plating apparatuscharacterized by comprising a plating tank for holding a platingsolution; an anode disposed so as to be immersed in the plating solutionin the plating tank; a regulation plate disposed between the anode and aplating workpiece disposed so as to face the anode; and a plating powersupply for supply a current between the anode and the plating workpieceto carry out plating, wherein the regulation plate is disposed so as toseparate the plating solution held in the plating tank into a platingsolution on the anode side and a plating solution on the platingworkpiece side, and a plating solution passage is formed in theregulation plate for allowing an electric field to uniformly passtherethrough and allowing the plating solution to pass therethrough.

[0029] By thus allowing the electric field produced between the anodeand the plating workpiece in the plating tank to pass uniformly throughthe plating solution passage without leaking out of the plating solutionpassage, distortion or deviation of the electric field can be adjustedand corrected so as to equalize a potential distribution over an entiresurface of the plating workpiece, thereby enhancing a within waferuniformity of a metal film formed on the plating workpiece.

[0030] The length of the plating solution passage is properly determineddepending upon the shape of the plating tank, the distance between theanode and the plating workpiece, and the like. However, the length isgenerally 10 to 90 mm, preferably 20 to 75 mm, more preferably 30 to 60mm.

[0031] Preferably, the plating solution passage is defined by an innercircumferential surface of a cylindrical member or a rectangular block.This arrangement can simplify the structure.

[0032] It is desirable that a large number of through-holes having asize such as to prevent leakage of an electric field be formed in acircumferential wall of the cylindrical member. With this arrangement,the plating solution is allowed to pass through the through-holes formedin the circumferential wall of the cylindrical member while preventingleakage of the electric field. Accordingly, the concentration of theplating solution is prevented from being different between the insideand outside of the cylindrical member. With respect to the shape of thethrough-holes, for example, fine holes, slit-like elongated holes, crossholes extending vertically and horizontally, and a combination thereofmay be exemplified.

[0033] According to a preferred aspect of the present invention, theplating apparatus comprises an agitating mechanism provided in at leastone of a space between the plating workpiece and the regulation plateand a space between the anode and the regulation plate for agitating theplating solution held in the plating tank. By agitating the platingsolution during plating, the concentration of the plating solutioncontaining metal ions and various additives can be made uniform in theplating tank, and the plating solution having a uniform concentrationcan be supplied to the plating workpiece. Accordingly, a metal filmhaving a more uniform thickness can be formed more rapidly.

[0034] The agitating mechanism is preferably a paddle-type agitatingmechanism having a paddle which reciprocates parallel to the platingworkpiece.

[0035] The agitating mechanism may comprise a plating solution injectiontype agitating mechanism having a plurality of plating solutioninjection nozzles for ejecting the plating solution toward the platingworkpiece. By injecting the plating solution from the plurality ofplating solution injection nozzles toward the plating workpiece, theplating solution in the plating tank can be agitated so as to uniformizethe plating solution concentration and, simultaneously, to sufficientlysupply components of the plating solution to the plating workpiece.Thus, a metal film having a more uniform thickness can be formed morerapidly.

[0036] The plating solution passage may be formed in the regulationplate integrally with the regulation plate. A thick regulation plate maybe used, and a through-hole may be formed in the regulation plate so asto serve as a plating solution passage.

[0037] The present invention provides yet another plating apparatuscomprising a plating tank for holding a plating solution; an anodedisposed so as to be immersed in the plating solution in the platingtank; a regulation plate disposed between the anode and a platingworkpiece disposed so as to face the anode for separating the platingsolution held in the plating tank into a plating solution on the anodeside and a plating solution on the plating workpiece side, theregulation plate having a plating solution passage for allowing anelectric field to uniformly pass therethrough and allowing the platingsolution to pass therethrough; a plating power supply for supply acurrent between the anode and the plating workpiece to carry outplating; and an electric field adjustment ring disposed at an end of theplating solution passage on the plating workpiece side for adjusting anelectric field at a peripheral portion of the plating workpiece.

[0038] By adjusting an electric field at a peripheral portion of theplating workpiece by the electric field adjustment ring, an electricfield produced between the anode and the plating workpiece can beuniformized over an entire surface of the plating workpiece, includingan edge portion of the plating workpiece, which serves as anelectrically receiving portion. Therefore, a within wafer uniformity ofa metal film formed on the plating workpiece can be further enhanced.

[0039] The shape of the electric field adjustment ring may be properlydetermined depending upon the shape of the plating tank, the shape ofthe plating workpiece, the distance between the anode and the platingworkpiece, and the like. The width of the ring is generally set to be ina range of 1 to 20 mm, preferably 3 to 17 mm, more preferably 5 to 15mm.

[0040] A gap between the electric field adjustment ring and the platingworkpiece is generally set to be in a range of 0.5 to 30 mm, preferably1 to 15 mm, more preferably 1.5 to 6 mm.

[0041] According to a preferred aspect of the present invention, theplating solution passage is defined by an inner circumferential surfaceof a cylindrical member, and the electric field adjustment ring isconnected to an end of the cylindrical member on the plating workpieceside.

[0042] Alternatively, the plating solution passage may be defined by aninner circumferential surface of a cylindrical member, and the electricfield adjustment ring may be disposed at an end of the cylindricalmember on the plating workpiece side so as to be separated from thecylindrical member. With such a separated plating solution passage, thecylindrical member and the electric field adjustment ring can beseparated so as to offer a broader choice.

[0043] Alternatively, the plating solution passage may be defined by aninner circumferential surface of a cylindrical member, and the electricfield adjustment ring may be formed on an end surface of the platingworkpiece side. With this arrangement, the number of parts can bereduced.

BRIEF DESCRIPTION OF DRAWINGS

[0044]FIG. 1 is an overall layout of a plating facility having a platingapparatus according to an embodiment of the present invention;

[0045]FIG. 2 is a schematic view of a transfer robot provided in aplating space of a plating processing apparatus shown in FIG. 1;

[0046]FIG. 3 is a schematic cross-sectional view of a plating apparatusprovided in the plating processing apparatus shown in FIG. 1;

[0047]FIG. 4 is a schematic perspective view of a main portion of theplating apparatus shown in FIG. 3;

[0048]FIG. 5 is a plan view of a regulation plate provided in theplating apparatus shown in FIG. 3;

[0049]FIG. 6 is a schematic diagram illustrating a state of a metal film(plated film) formed by the plating apparatus shown in FIG. 3;

[0050]FIGS. 7A through 7E are cross-sectional diagrams sequentiallyillustrating a process of forming a bump (protruding electrode) on asubstrate;

[0051]FIG. 8 is a plan view showing another example of a regulationplate;

[0052]FIG. 9 is a plan view showing still another example of aregulation plate;

[0053]FIG. 10 is a plan view showing yet another example of a regulationplate;

[0054]FIG. 11 is a plan view showing yet another example of a regulationplate;

[0055]FIG. 12 is a plan view showing yet another example of a regulationplate;

[0056]FIG. 13 is a plan view showing yet another example of a regulationplate;

[0057]FIG. 14 is a plan view showing yet another example of a regulationplate;

[0058]FIG. 15 is a plan view showing yet another example of a regulationplate;

[0059]FIG. 16 is a plan view showing yet another example of a regulationplate;

[0060]FIG. 17 is a plan view showing yet another example of a regulationplate;

[0061]FIG. 18 is a plan view showing yet another example of a regulationplate;

[0062]FIG. 19 is a plan view showing yet another example of a regulationplate;

[0063]FIG. 20 is a schematic cross-sectional view showing a platingapparatus according to another embodiment of the present invention;

[0064]FIG. 21A is a perspective view showing a regulation plate and acylindrical member provided in the plating apparatus shown in FIG. 20;

[0065]FIG. 21B is a front view of FIG. 21A;

[0066]FIG. 22 is a schematic diagram illustrating a state of a metalfilm (plated film) formed by the plating apparatus shown in FIG. 20;

[0067]FIG. 23 is a schematic cross-sectional view showing a platingapparatus according to still another embodiment of the presentinvention;

[0068]FIG. 24A is a perspective view showing another example of aregulation plate and a cylindrical member;

[0069]FIG. 24B is a front view of FIG. 24A;

[0070]FIG. 25A is a perspective view showing still another example of aregulation plate and a cylindrical member;

[0071]FIG. 25B is a front view of FIG. 25A;

[0072]FIG. 26A is a perspective view showing yet another example of aregulation plate and a cylindrical member;

[0073]FIG. 26B is a front view of FIG. 26A;

[0074]FIG. 27A is a perspective view showing yet another example of aregulation plate and a cylindrical member;

[0075]FIG. 27B is a front view of FIG. 27A;

[0076]FIG. 28 is a schematic cross-sectional view showing a platingapparatus according to yet another embodiment of the present invention;

[0077]FIG. 29A is a perspective view showing a regulation plate, acylindrical member, and an electric field adjustment ring provided inthe plating apparatus shown in FIG. 28;

[0078]FIG. 29B is a front view of FIG. 29A;

[0079]FIG. 30 is a schematic diagram illustrating a metal film (platedfilm) formed by the plating apparatus shown in FIG. 28;

[0080]FIG. 31 is a schematic cross-sectional view showing a platingapparatus according to yet another embodiment of the present invention;

[0081]FIG. 32A is a perspective view showing another example of aregulation plate, a cylindrical member, and an electric field adjustmentring;

[0082]FIG. 32B is a front view of FIG. 32A;

[0083]FIG. 33A is a perspective view showing still another example of aregulation plate, a cylindrical member, and an electric field adjustmentring;

[0084]FIG. 33B is a front view of FIG. 33A;

[0085]FIG. 34A is a perspective view showing yet another example of aregulation plate, a cylindrical member, and an electric field adjustmentring;

[0086]FIG. 34B is a front view of FIG. 34A;

[0087]FIG. 35A is a perspective view showing yet another example of aregulation plate, a cylindrical member, and an electric field adjustmentring;

[0088]FIG. 35B is a front view of FIG. 35A;

[0089]FIG. 36 is a schematic cross-sectional view showing a platingapparatus according to yet another embodiment of the present invention;

[0090]FIG. 37 is a schematic cross-sectional view showing an example ofa conventional plating apparatus;

[0091]FIG. 38 is a schematic perspective view showing another example ofa conventional plating apparatus;

[0092]FIG. 39 is a schematic perspective view showing still anotherexample of a conventional plating apparatus; and

[0093]FIGS. 40A through 40C are schematic diagrams illustrating variousstates of metal films (plated films) formed by conventional platingapparatuses.

BEST MODE FOR CARRYING OUT THE INVENTION

[0094] Embodiments of the present invention will be described below withreference to the drawings. The following embodiments show examples inwhich a substrate such as a semiconductor wafer is used as a platingworkpiece.

[0095]FIG. 1 shows an overall layout of a plating facility having aplating apparatus according to an embodiment of the present invention.The plating facility is designed so as to automatically perform all theplating processes including pretreatment of a substrate, plating, andposttreatment of the plating, in a successive manner. The interior of anapparatus frame 110 having an armored panel attached thereto is dividedby a partition plate 112 into a plating space 116 for performing aplating process of a substrate and treatments of the substrate to whicha plating solution is attached, and a clean space 114 for performingother processes, i.e. processes not directly involving a platingsolution. Two substrate holders 160 (see FIG. 2) are arranged inparallel, and substrate attachment/detachment stages 162 to attach asubstrate to and detach a substrate from each substrate holder 160 areprovided as a substrate delivery section on a partition portionpartitioned by the partition plate 112, which divides the plating space116 from the clean space 114. Loading/unloading ports 120, on whichsubstrate cassettes storing substrates are mounted, are connected to theclean space 114. Further, the apparatus frame 110 has a console panel121 provided thereon.

[0096] In the clean space 114, there are disposed at four corners analigner 122 for aligning an orientation flat or a notch of a substratewith a predetermined direction, two cleaning/drying devices 124 forcleaning a plated substrate and rotating the substrate at a high speedto spin-dry the substrate, and a pretreatment device 126 for carryingout a pretreatment of a substrate, e.g., according to the presentembodiment, a rinsing pretreatment including injecting pure water towarda front face (surface to be plated) of a substrate to thereby clean thesubstrate surface with pure water and, at the same time, wet thesubstrate surface with pure water so as to enhance a hydrophilicity ofthe substrate surface. Further, a first transfer robot 128 is disposedsubstantially at the center of these processing devices, i.e. thealigner 122, the cleaning/drying devices 124, and the pretreatmentdevice 126, to thereby transfer and deliver a substrate between theprocessing devices 122, 124, and 126, the substrateattachment/detachment stages 162, and the substrate cassettes mounted onthe loading/unloading ports 120.

[0097] The aligner 122, the cleaning/drying devices 124, and thepretreatment device 126 disposed in the clean space 114 are designed soas to hold and process a substrate in a horizontal state in which afront face of the substrate faces upward. The transfer robot 128 isdesigned so as to transfer and deliver a substrate in a horizontal statein which a front face of the substrate faces upward.

[0098] In the plating space 116, in the order from the partition plate112, there are disposed a stocker 164 for storing or temporarily storingthe substrate holders 160, an activation treatment device 166 foretching, for example, an oxide film, having a large electric resistance,on a seed layer formed on a surface of a substrate with a chemicalliquid such as sulfuric acid or hydrochloric acid to remove the oxidefilm, a first rinsing device 168 a for rinsing the surface of thesubstrate with pure water, a plating apparatus 170 for carrying outplating, a second rinsing device 168 b, and a blowing device 172 fordewatering the plated substrate. Two second transfer robots 174 a and174 b are disposed beside these devices so as to be movable along a rail176. One of the second transfer robots 174 a transfers the substrateholders 160 between the substrate attachment/detachment stages 162 andthe stocker 164. The other of the second transfer robots 174 b transfersthe substrate holders 160 between the stocker 164, the activationtreatment device 166, the first rinsing device 168 a, the platingapparatus 170, the second rinsing device 168 b, and the blowing device172.

[0099] As shown in FIG. 2, each of the second transfer robots 174 a and174 b has a body 178 extending in a vertical direction and an arm 180which is vertically movable along the body 178 and rotatable about itsaxis. The arm 180 has two substrate holder retaining portions 182provided in parallel for detachably retaining the substrate holders 160.The substrate holder 160 is designed so as to hold a substrate W in astate in which a front face of the substrate is exposed while aperipheral portion of the substrate is sealed, and to be capable ofattaching the substrate W to the substrate holder 160 and detaching thesubstrate W from the substrate holder 160.

[0100] The stocker 164, the activation treatment device 166, the rinsingdevices 168 a, 168 b, and the plating apparatus 170 are designed so asto engage with outwardly projecting portions 160 a provided at both endsof each substrate holder 160 to thus support the substrate holders 160in a state such that the substrate holders 160 are suspended in avertical direction. The activation treatment device 166 has twoactivation treatment tanks 183 for holding a chemical liquid therein. Asshown in FIG. 2, the arm 180 of the second transfer robot 174 b holdingthe substrate holders 160, which are loaded with the substrates W, in avertical state is lowered so as to engage the substrate holders 160 withupper ends of the activation treatment tanks 183 to support thesubstrate holders 160 in a suspended manner as needed. Thus, theactivation treatment device 166 is designed so that the substrateholders 160 are immersed together with the substrates W in the chemicalliquid in the activation treatment tanks 183 to carry out an activationtreatment.

[0101] Similarly, the rinsing devices 168 a and 168 b have two rinsingtanks 184 a and two rinsing tanks 184 b which hold pure water therein,respectively, and the plating apparatus 170 has a plurality of platingtanks 186 which hold a plating solution therein. The rinsing devices 168a, 168 b and the plating apparatus 170 are designed so that thesubstrate holders 160 are immersed together with the substrates W in thepure water in the rinsing tanks 184 a, 184 b or the plating solution inthe plating tanks 186 to carry out rinsing treatment or plating in thesame manner as described above. The arm 180 of the second transfer robot174 b holding the substrate holders 160 with substrates W in a verticalstate is lowered, and air or inert gas is injected toward the substratesW mounted on the substrate holders 160 to blow away a liquid attached tothe substrate holders 160 and the substrates W and to dewater thesubstrates W. Thus, the blowing device 172 is designed so as to carryout blowing treatment.

[0102] As shown in FIGS. 3 and 4, each plating tank 186 in the platingapparatus 170 is designed so as to hold a plating solution 10 therein.Thus, the substrates W, which are held in a state such that the frontfaces (surfaces to be plated) are exposed while peripheral portions ofthe substrate holders 160 are water-tightly sealed, are immersed in theplating solution 10.

[0103] Overflow tanks 46 are provided at both sides of the plating tank186 for receiving a plating solution 10 overflowing upper ends ofoverflow weirs 44 of the plating tank 186. The overflow tanks 46 and theplating tank 186 are connected through a circulation pipe 48. Thecirculation pipe 48 has a circulating pump 50, a thermostatic unit 52,and a filter 54 provided in the circulation pipe 48. A plating solution10 supplied into the plating tank 186 by operation of the circulatingpump 50 fills the plating tank 186, then overflows the overflow weirs44, flows into the overflow tanks 46, and returns to the circulatingpump 50. Thus, the plating solution 10 is circulated.

[0104] An anode 56 having a circular shape corresponding to the shape ofthe substrate W is held by an anode holder 58 and provided vertically inthe plating tank 186. Thus, when the plating solution 10 is filled inthe plating tank 186, the anode 56 is immersed in the plating solution10. Further, a regulation plate 60 is provided between the anode 56 andthe substrate holder 160 to partition the interior of the plating tank186 into an anode side chamber 40 a and a substrate side chamber 40 band to separate the plating solution 10 held in the plating tank 186into an anode side plating solution and a substrate side platingsolution.

[0105] A paddle-type agitating mechanism 64 having a plurality ofpaddles 62 extending vertically downward is disposed between thesubstrate holder 160 and the regulation plate 60. The paddles 62 arereciprocated within the plating solution in the substrate side chamber40 b in parallel to the substrate W held by the substrate holder 160,thereby stirring the plating solution in the substrate side chamber 40b.

[0106] The regulation plate 60 has a thickness of, for example, about0.5 to 10 mm and is made of a dielectric material including PVC, PP,PEEK, PES, HT-PVC, PFA, PTFE, and other resin materials. A through-holegroup 68 including a large number of through-holes 66 is provided in apredetermined area of the regulation plate 60, which is substantiallythe entire area facing the surface of the substrate W when the substrateW is held by the substrate holder 160 and located at a predeterminedplating position in the plating tank 186, and which is a circular areasimilar to the shape of the substrate W.

[0107] According to the present embodiment, as particularly shown inFIG. 5, the through-holes 66 are formed by slit-like elongated holesextending linearly in a horizontal direction. The through-holes(elongated holes) 66 are lineally arranged in parallel within a circulararea corresponding to the shape of the substrate W so as to form thethrough-hole group 68. The through-holes (elongated holes) 66 generallyhave a width of about 0.5 to 20 mm, preferably about 1 to 15 mm. Thelength of the through-hole 66 is determined depending upon the size(diameter) of the substrate W.

[0108] Thus, the through-hole group 68 including a large number ofthrough-holes 66 is provided in the regulation plate 60 so that anelectric field leaks through the respective through-holes 66 at the timeof plating, and that the leaked electric field spreads uniformly.Accordingly, a potential distribution can be made more uniform over theentire surface (surface to be plated) of the substrate W, and a withinwafer uniformity of a metal film formed on the surface of the substrateW can be enhanced. Further, the plating solution 10 is prevented frompassing through a large number of through-holes 66 formed in theregulation plate 60 provided in the plating tank 186. Accordingly,non-uniform film thickness is prevented from being caused to a metalfilm formed on the surface of the substrate W due to influence of a flowof the plating solution 10 (return flow of the plating solution).

[0109] Particularly, the use of slit-like elongated holes as thethrough-holes 66 can prevent the plating solution 10 from passingthrough the through-holes (elongated holes) 66 and simultaneouslypromote leakage of the electric field. Further, by forming thethrough-hole group 68, including a large number of through-holes 66,substantially in the entire area facing the surface of the substrate Wwhich is a circular area similar to the shape of the substrate W, ametal film having a good film thickness uniformity can be formed in alldirections on the surface of the substrate W.

[0110] With the plating apparatus 170, a plating solution 10 is firstfilled in the plating tank 186 and circulated as described above. Inthis state, the substrate holder 160 holding the substrate W is loweredto locate the substrate W at a predetermined position within the platingtank 186 at which the substrate W is immersed in the plating solution10. The anode 56 is connected via a conductor 22 a to an anode of aplating power supply 24, and the substrate W is connected via aconductor 22 b to a cathode of the plating power supply 24. At the sametime, the paddle-type agitating mechanism 64 is operated so as toreciprocate the paddles 62 along the surface of the substrate W tothereby agitate the plating solution 10 in the substrate side chamber 40b. As a result, a metal is deposited on the surface of the substrate Wso as to form a metal film on the surface of the substrate W.

[0111] At that time, as described above, an electric field leaks througha large number of through-holes 66 formed in the regulation plate 60,and the leaked electric field spreads uniformly. Accordingly, apotential distribution can be made more uniform over the entire frontface (surface to be plated) of the substrate W, and a metal film Phaving an enhanced within wafer uniformity can be formed on the surfaceof the substrate W as shown in FIG. 6. Further, by agitating the platingsolution 10 between the substrate W and the regulation plate 60 with thepaddles 62 during plating, the directionality of the flow of the platingsolution can be eliminated, and simultaneously sufficient ions can besupplied more uniformly to the surface of the substrate W. Therefore, ametal film having a more uniform thickness can be formed more rapidly.

[0112] After completion of the plating, the plating power supply 24 isdisconnected from the substrate W and the anode 56, and the substrateholder 160 is pulled up together with the substrate W. After necessarytreatments such as water-cleaning and rinsing of the substrate W, theplated substrate W is transferred to a subsequent process.

[0113] A series of bump plating processes in the plating facility thusconstructed will be described below with reference to FIGS. 7A through7E. First, as shown in FIG. 7A, a seed layer 500 is deposited as afeeding layer on a surface of a substrate W, and a resist 502 having aheight H of, for example, about 20 to 120 μm is applied onto the entiresurface of the seed layer 500. Thereafter, an opening 502 a having adiameter D₁ of, for example, about 20 to 200 μm is formed at apredetermined position of the resist 502. Substrates W thus prepared arehoused in a substrate cassette in a state such that front faces(surfaces to be plated) of the substrates face upward. The substratecassette is mounted on the loading/unloading port 120.

[0114] One of the substrates W is taken out of the substrate cassettemounted on the loading/unloading port 120 by the first transfer robot128 and placed on the aligner 122 to align an orientation flat or anotch of the substrate with a predetermined direction. The substrate Wthus aligned is transferred to the pretreatment device 126 by the firsttransfer robot 128. In the pretreatment device 126, a pretreatment(rinsing pretreatment) using pure water as a pretreatment liquid iscarried out. On the other hand, two substrate holders 160 which havebeen stored in a vertical state in the stocker 164 are taken out by thesecond transfer robot 174 a, rotated through 90° so that the substrateholders 160 are brought into a horizontal state, and then placed inparallel on the substrate attachment/detachment stages 162.

[0115] Then, the substrates W which have been subjected to theaforementioned pretreatment (rinsing pretreatment) are loaded into thesubstrate holders 160 placed on the substrate attachment/detachmentstages 162 in a state such that peripheral portions of the substratesare sealed. The two substrate holders 160 which have been loaded withthe substrates W are simultaneously retained, lifted, and thentransferred to the stocker 164 by the second transfer robot 174 a. Thesubstrate holders 160 are rotated through 90° into a vertical state andlowered so that the two substrate holders 160 are held (temporarilystored) in the stocker 164 in a suspended manner. The above operation iscarried out repeatedly in a sequential manner, so that substrates aresequentially loaded into the substrate holders 160, which are stored inthe stocker 164, and are sequentially held (temporarily stored) in thestocker 164 at predetermined positions in a suspended manner.

[0116] On the other hand, the two substrate holders 160 which have beenloaded with the substrates and temporarily stored in the stocker 164 aresimultaneously retained, lifted, and then transferred to the activationtreatment device 166 by the second transfer robot 174 b. Each substrateis immersed in a chemical liquid such as sulfuric acid or hydrochloricacid held in the activation treatment tank 183 to thereby etch an oxidefilm, having a large electric resistance, formed on the surface of theseed layer so as to expose a clean metal surface. The substrate holders160 which have been loaded with the substrates are transferred to thefirst rinsing device 168 a in the same manner as described above torinse the surfaces of the substrates with pure water held in the rinsingtanks 184 a.

[0117] The substrate holders 160 which have been loaded with the rinsedsubstrates are transferred to the plating apparatus 170 in the samemanner as described above. Each substrate W is supported in a suspendedmanner by the plating tank 186 in a state such that the substrate W isimmersed in the plating solution 10 in the plating tank 186 to thuscarry out plating on the surface of the substrate W. After apredetermined period of time has elapsed, the substrate holders 160which have been loaded with the substrates are retained again and pulledup from the plating tank 186 by the second transfer robot 174 b. Thus,the plating process is completed.

[0118] Thereafter, the substrate holders 160 are transferred to thesecond rinsing device 168 b in the same manner as described above. Thesubstrate holders 160 are immersed in pure water in the rinsing tanks184 b to clean the surfaces of the substrates with pure water. Then, thesubstrate holders 160 which have been loaded with the substrates aretransferred to the blowing device 172 in the same manner as describedabove. In the blowing device 172, inert gas or air is injected towardthe substrates to blow away a plating solution and water dropletsattached to the substrate holders 160. Thereafter, the substrate holders160 which have been loaded with the substrates are returned topredetermined positions in the stocker 164 and held in a suspended statein the same manner as described above.

[0119] The second transfer robot 174 b sequentially performs the aboveoperation repeatedly so that the substrate holders 160 which have beenloaded with the plated substrates are sequentially returned topredetermined positions in the stocker 164 and held in a suspendedmanner.

[0120] On the other hand, the two substrate holders 160 which have beenloaded with the plated substrates are simultaneously retained and placedon the substrate attachment/detachment stages 162 by the second transferrobot 174 a in the same manner as described above.

[0121] The first transfer robot 128 disposed in the clean space 114takes the substrate out of the substrate holders 160 placed on thesubstrate attachment/detachment stages 162 and transfers the substrateto either one of the cleaning/drying devices 124. In the cleaning/dryingdevice 124, the substrate held in a horizontal state such that the frontface of the substrate faces upward is cleaned with pure water or thelike and rotated at a high speed to spin-dry the substrate. Thereafter,the substrate is then returned to the substrate cassette mounted on theloading/unloading port 120 by the first transfer robot 128. Thus, aseries of plating processes is completed. As a result, as shown in FIG.7B, a substrate W having a plated film 504 grown in the opening 502 aformed in the resist 502 can be obtained.

[0122] The spin-dried substrate W as described above is immersed in asolvent such as acetone at a temperature of, for example, 50 to 60° C.to remove the resist 502 from the substrate W as shown in FIG. 7C.Further, as shown in FIG. 7D, an unnecessary seed layer 502, which isexposed after plating, is removed. Next, the plated film 504 formed onthe substrate W is reflowed to form a bump 506 having a round shape dueto surface tension. The substrate W is then annealed at a temperatureof, for example, 100° C. or more to remove residual stress in the bump506.

[0123] According to this embodiment, delivery of substrates in theplating space 116 is performed by the second transfer robots 174 a and174 b disposed in the plating space 116, whereas delivery of substratesin the clean space 114 is performed by the first transfer robot 128disposed in the clean space 114. Accordingly, it is possible to improvethe cleanliness around a substrate in the plating processing apparatuswhich performs all the plating processes including pretreatment of asubstrate, plating, and posttreatment of the plating, in a successivemanner, and to increase a throughput of the plating processingapparatus. Further, it is possible to reduce loads on facilitiesassociated with the plating processing apparatus and to achievedownsizing of the plating processing apparatus.

[0124] According to the present embodiment, a plating tank 186 having asmall footprint is used in the plating apparatus 170 for carrying outplating. Accordingly, it is possible to achieve further downsizing ofthe plating apparatus having a large number of plating tanks 186 andreduce loads on associated facilities in a plant. In FIG. 1, one of thetwo cleaning/drying devices 124 may be replaced with a pretreatmentdevice.

[0125]FIGS. 8 through 19 show various examples of a through-hole groupincluding a large number of through-holes in a regulation plate 60.Specifically, FIG. 8 shows an example in which through-holes 66 a areformed by slit-like elongated holes extending linearly in a verticaldirection, and the through-holes (elongated holes) 66 a are arrangedlinearly in parallel in a circular area corresponding to the shape of asubstrate W so as to form a through-hole group 68 a. FIG. 9 shows anexample in which through-holes (elongated holes) 66 b are arrangedlinearly in parallel in a rectangular area corresponding to the shape ofa substrate W so as to form a through-hole group 68 b, which is suitablefor a rectangular substrate W.

[0126]FIG. 10 shows an example in which a through-hole group 68 c isformed by a plurality of through-holes (elongated holes) 66 c which areslit-like elongated holes extending linearly substantially across theentire width of an area of a regulation plate 60 facing a surface of asubstrate W. In this case, when a rectangular substrate W is used, asshown in FIG. 11, through-holes (elongated holes) 66 d may be arrangedin parallel in a rectangular area corresponding to the shape of thesubstrate W so as to form a through-hole group 68 d. Further, thethrough-holes 66 d may be arranged so as to extend linearly in avertical direction, which is not shown.

[0127]FIG. 12 shows an example in which through-holes (cross holes) 66 ewhich are cross holes extending crosswise in vertical and horizontaldirections are arranged uniformly in a circular area so as to form athrough-hole group 68 e. In this case, when a rectangular substrate W isused, as shown in FIG. 13, through-holes (cross holes) 66 f may bearranged uniformly in a rectangular area corresponding to the shape ofthe substrate W so as to form a through-hole group 68 f.

[0128]FIG. 14 shows an example in which a plurality of through-holes(fine holes) 66 g which are fine holes is distributed uniformly in acircular area so as to form a through-hole group 68 g. In thisillustrated example, the diameter of each through-hole (fine hole) 66 gis set to be 2 mm, and 633 holes are provided in total. Although thediameters of the through-holes 66 g as well as small holes (peripheralholes) 66 h ₂ through 66 h ₅ described below may be set arbitrarilywithin a range of, for example, 1 to 20 mm, they should preferably be ina range of about 2 to 10 mm. When the through-hole group 68 g is formedby the through-holes (fine holes) 66 g, productivity of the regulationplate 60 can be increased.

[0129]FIG. 15 shows an example in which a through-hole group 68 h isformed by a plurality of through-holes 66 h having different diameters,i.e. a large hole (central hole) 66 h ₁ having a large diameter andlocated at a central portion, and small holes (peripheral holes) 66 h ₂through 66 h ₅ arranged outside of the large hole 66 h ₁ along acircumferential direction in a plurality of arrays (four arrays in FIG.15) having diameters gradually reduced in a radial direction. Thediameter of the large hole (central hole) 66 h ₁ is set to be 84 mm inthis example. Although the diameter of the large hole may be setarbitrarily within a range of, for example, 50 to 300 mm, it shouldpreferably be in a range of about 30 to 100 mm. The diameters of thesmall holes (peripheral holes) 66 h ₂ through 66 h ₅ are set to be 10mm, 8 mm, 7 mm, and 6 mm, respectively.

[0130]FIG. 16 shows an example in which a through-hole group 68 i isformed by a plurality of through-holes 66 i including a central hole 66i ₁ located at a central portion, and elongated holes 66 i ₂ through 66i ₆ arranged outside of the central hole 66 i ₁ along a circumferentialdirection in a plurality of arrays (five arrays in FIG. 16). In thisexample, the diameter of the central hole 66 i ₁ is set to be 34 mm, andthe widths of the elongated holes 66 i ₂ through 66 i ₆ are set to be 27mm, 18.5 mm, 7 mm, 7 mm, and 7 mm, respectively.

[0131]FIG. 17 shows an example in which a through-hole group 68 j isformed by a plurality of through-holes 66 j including a large hole(central hole) 66 j ₁ having a large diameter and located at a centralportion, elongated holes 66 j ₂ arranged outside of the central hole 66j ₁ along a circumferential direction, and small holes (peripheralholes) 66 j ₃ through 66 j ₆ arranged outside of the elongated holes 66j ₂ in a plurality of arrays (four arrays in FIG. 17) having diametersgradually reduced in a radial direction. In this example, the diameterof the large hole (central hole) 66 j, is set to be 67 mm, the width ofthe elongated hole 66 j ₂ is set to be 17 mm, and the diameters of thesmall holes (peripheral holes) 66 j ₃ through 66 j ₆ are set to be 9 mm,8 mm, 7 mm, and 6 mm, respectively.

[0132]FIG. 18 shows an example in which a through-hole group 68 k isformed by a plurality of through-holes 66 k including a large hole(central hole) 66 k, having a large diameter and located at a centralportion, elongated holes 66 k ₂, 66 k ₃ arranged outside of the centralhole 66 k ₁ along a circumferential direction in a plurality of arrays(two arrays in FIG. 18), and small holes (peripheral holes) 66 k ₄, 66 k₅ arranged outside of the elongated holes 66 k ₃ in a plurality ofarrays (two arrays in FIG. 18) having diameters gradually reduced in aradial direction. In this example, the diameter of the large hole(central hole) 66 k ₁ is set to be 80 mm, the widths of the elongatedholes 66 k ₂, 66 k ₃ are set to be 7 mm, and the diameters of the smallholes (peripheral holes) 66 k ₄, 66 k ₅ are set to be 6 mm and 4 mm,respectively.

[0133]FIG. 19 shows an example in which a through-hole group 68 l isformed by a plurality of through-holes 66 l including a large hole(central hole) 66 l ₁ having a large diameter and located at a centralportion, and a plurality of slit-like elongated holes 66 l ₂ arrangedoutside of the central hole 66 l ₁ at a predetermined pitch along acircumferential direction and extending linearly in a radial direction.The widths of the elongated holes 66 l ₂ are generally in a range ofabout 0.5 to 20 mm, preferably about 1 to 15 mm. The lengths of theelongated holes 66 l ₂ are set arbitrarily according to the shape of aplating workpiece.

[0134] Thus, a through-hole group is formed by combination of aplurality of through-holes having desired shapes, such as a plurality offine holes, a plurality of holes having different diameters, andslit-like elongated holes. Accordingly, a through-hole group can meetvarious requirements regarding plating sites, plating conditions, andthe like.

[0135] In the examples shown in FIGS. 14 through 19, through-holes arearranged in a circular area so as to form a through-hole group. However,as described above, when a rectangular substrate is used, through-holesmay be arranged, as a matter of course, in a rectangular areacorresponding to the shape of the substrate so as to form a through-holegroup.

[0136] As described above, according to the present invention, anelectric field leaks through a large number of through-holes formed in aregulation plate provided in the plating tank, and the leaked electricfield spreads uniformly. Accordingly, a potential distribution can bemade more uniform over the entire surface of a plating workpiece, and awithin wafer uniformity of a metal film formed on the surface of theplating workpiece can be enhanced. Further, a plating solution isprevented from passing through a large number of through-holes formed inthe regulation plate provided in the plating tank 186. Accordingly,non-uniform film thickness is prevented from being caused to a metalfilm formed on the surface of the plating workpiece due to influence ofa flow of the plating solution.

[0137]FIG. 20 shows a plating apparatus 170 a according to anotherembodiment of the present invention, and FIGS. 21A and 21B show aregulation plate and a cylindrical member forming a plating solutionpassage which are used in the plating apparatus 170 a. The platingapparatus 170 a differs from the apparatus shown in FIGS. 3 through 5 inthat the plating apparatus 170 a employs a regulation plate 60 having athickness of, for example, about 0.5 to 10 mm and having a central hole60 a at the center thereof which faces a substrate W held by a substrateholder 160 and has an inside diameter D corresponding to the outsidediameter of the substrate W, and that a cylindrical member 200 having aninside diameter equal to the inside diameter D of the central hole 60 ais concentrically connected to a surface of the regulation plate 60 onthe substrate holder 160 side continuously with the central hole 60 a soas to define a plating solution passage 200 a inside an innercircumferential surface of the cylindrical member 200 for allowing anelectric field to pass uniformly therethrough and allowing a platingsolution 10 to pass therethrough. As with the regulation plate 60, thecylindrical member 200 is made of a dielectric material including PVC,PP, PEEK, PES, HT-PVC, PFA, PTFE, and other resin materials. Otherconstructions are the same as those shown in FIGS. 3 through 5.

[0138] The inside diameters D of the central hole of the regulationplate 60 and the cylindrical member 200 are generally set to beapproximately in a range of ±10 mm of an outside diameter (platedsurface outside diameter) of a surface of a substrate W to be plated,preferably in a range of ±5 mm of an outside diameter of a surface to beplated, more preferably in a range of ±1 mm of an outside diameter of asurface to be plated. The length L of the cylindrical member 200 mayproperly be set depending upon the shape of the plating tank 186, thedistance between the anode 56 and the substrate W, and the like.However, the length L is generally set to be in a range of 10 to 90 mm,preferably 20 to 75 mm, more preferably 30 to 60 mm.

[0139] Thus, an electric field produced between the anode 56 and thesubstrate W in the plating tank 186 passes along the plating solutionpassage 200 a, i.e., passes uniformly through the cylindrical member 200without leaking out of the cylindrical member 200. Accordingly,distortion and deviation of the electric field can be adjusted andcorrected so as to equalize a potential distribution over the entiresurface of the substrate W. As a result, as shown in FIG. 22, a metalfilm P having an enhanced within wafer uniformity can be formed on thesurface of the substrate W although it has a slightly thicker film at anedge portion of the substrate W.

[0140] Specifically, a regulation plate 60 generally is as thin as about0.5 to 10 mm. Therefore, with a regulation plate 60 having only acentral hole 60 a formed therein, an electric field produced between theanode 56 and a substrate W in the plating tank 186 is not sufficientlyregulated, and distortion or deviation of an electric field is caused.Accordingly, the substrate tends to be thicker at an edge portion, whichserves as an electrically receiving portion. According to the presentexample, passing of an electric field is regulated over the length L ofthe cylindrical member 200, so that the above drawback is solved. Thus,a within wafer uniformity of a metal film can be enhanced.

[0141] In this example, as in the examples shown in FIGS. 3 through 5, apaddle-type agitating mechanism 64 having a plurality of paddles 62extending vertically downward is disposed between the cylindrical member200 and the substrate W held by the substrate holder 160. Thepaddle-type agitating mechanism 64 is operated during plating so as toreciprocate the paddles 62 along the surface of the substrate W, therebyagitating the plating solution 10 in a substrate side chamber 40 b.Accordingly, the directionality of the flow of the plating solution canbe eliminated, and simultaneously sufficient ions can be supplied moreuniformly to the surface of the substrate W. Therefore, a metal filmhaving a more uniform thickness can be formed more rapidly.

[0142]FIG. 23 shows a plating apparatus 170 b according to still anotherembodiment of the present invention. The plating apparatus 170 b differsfrom the apparatus shown in FIGS. 21 and 22 in that a plating solutioninjection type agitating mechanism 202 is disposed between thecylindrical member 200 and a substrate W held by the substrate holder160 instead of the paddle-type agitating mechanism 64. Specifically, theplating solution injection type agitating mechanism 202 has a platingsolution supply pipe 204, for example, in a ring shape, communicatingwith a circulation pipe 48 and immersed in the plating solution 10 inthe plating tank 186, and a plurality of plating solution injectionnozzles 206 attached to predetermined portions of the plating solutionsupply pipe 204 along a circumferential direction for ejecting theplating solution 10 toward the substrate W held by the substrate holder160. A plating solution 10 fed by a pump 50 is supplied to the platingsolution supply pipe 204 and injected from the plating solutioninjection nozzles 206 toward the substrate. Thus, the plating solution10 is introduced into the plating tank 186, overflows upper ends ofoverflow weirs 44, and is circulated.

[0143] Thus, the plating solution 10 is injected from a plurality ofplating solution injection nozzles 206 toward the substrate W.Accordingly, the plating solution 10 in the plating tank 186 can beagitated so as to uniformize the plating solution concentration and,simultaneously, to sufficiently supply components of the platingsolution 10 to the substrate W. Thus, a metal film having a more uniformthickness can be formed more rapidly.

[0144] In this example, the cylindrical member 200 is coupled to asurface of the regulation plate 60 on the substrate W side. However, asshown in FIG. 24B, an insertion hole 60 b may be formed in theregulation plate 60, and a cylindrical member 200 having an insidediameter D, a length L, and a plating solution passage 200 a inside aninner circumferential surface thereof may be inserted into the insertionhole 60 b. In this manner, the cylindrical member 200 may be held at apredetermined position along a longitudinal direction of the cylindricalmember 200. This arrangement ensures a sufficient length L as thecylindrical member 200 even if a distance between the regulation plate60 and the paddles 62 (see FIG. 20) or the plating solution supply pipe204 (see FIG. 23) is short.

[0145] Further, as shown in FIGS. 25A and 25B, the cylindrical member200 may have a circumferential wall having a large number ofthrough-holes 200 b which have a size such as to prevent leakage of anelectric field. With this arrangement, the plating solution 10 can passthrough the through-holes 200 b formed in the circumferential wall ofthe cylindrical member 200 while preventing leakage of the electricfield. Accordingly, the concentration of the plating solution isprevented from being different between the inside and outside of thecylindrical member 200. With respect to the shape of the through-holes,besides fine holes as in this example, slit-like elongated holes, crossholes extending vertically and horizontally, and a combination thereofmay be exemplified.

[0146] Further, as shown in FIGS. 26A and 26B, a regulation plate 210may be formed by a plate having a sufficient thickness, and athrough-hole having a predetermined inside diameter may be formed at apredetermined position in the regulation plate 210 so that thethrough-hole serves as a plating solution passage 210 a having apredetermined inside diameter D and a predetermined length L. In such acase, the number of parts can be reduced.

[0147] Furthermore, as shown in FIGS. 27A and 27B, a rectangular block212 having a sufficient thickness may be prepared so that a through-holeformed in the rectangular block 212 serves as a plating solution passage210 a having a predetermined inside diameter D and a predeterminedlength L, and the rectangular block 212 may be connected to a surface ofa regulation plate 60 having a center hole 60 a on the substrate W side.

[0148]FIG. 28 shows a plating apparatus 170 c according to yet anotherembodiment of the present invention, and FIGS. 29A and 29B shows aregulation plate, a cylindrical member forming a plating solutionpassage, and an electric field adjustment ring which are used in theplating apparatus 170 c shown in FIG. 28. The plating apparatus 170 cdiffers from the apparatus shown in FIGS. 20 and 21 in the followingpoints: An electric field adjustment ring 220 having the same insidediameter D as an inside diameter of the cylindrical member 200 and awidth A is concentrically attached to a substrate W side end surface ofthe cylindrical member 200 having a plating solution passage 200 adefined inside an inner circumferential surface thereof. The electricfield adjustment ring 220 is disposed close to a substrate W with a gapG1. Further, the paddle-type agitating mechanism 64 having a pluralityof paddles 62 extending vertically downward is disposed between theanode 56 and the regulation plate 60 in the anode side chamber 40 a soas to reciprocate the paddles 62 in parallel to the substrate W held bythe substrate holder 160, thereby agitating the plating solution. Thus,the paddle-type agitating mechanism 64 agitates the plating solution 10in the anode side chamber 40 a. Other constructions are the same asthose shown in FIGS. 20 and 21.

[0149] As with the regulation plate 60 and the cylindrical member 200,the electric field adjustment ring 220 is made of a dielectric materialincluding PVC, PP, PEEK, PES, HT-PVC, PFA, PTFE, and other resinmaterials. Other constructions are the same as those shown in FIGS. 3through 5. The shape of the electric field adjustment ring 220 mayproperly be set depending upon the shapes of the plating tank 186 andthe substrate W, the distance between the anode 56 and the substrate W,and the like. However, the width A is generally set to be in a range of1 to 20 mm, preferably 3 to 17 mm, more preferably 5 to 15 mm. A gap G1between the electric field adjustment ring 220 and the substrate W isgenerally set to be in a range of 0.5 to 30 mm, preferably 1 to 15 mm,more preferably 1.5 to 6 mm.

[0150] The electric field adjustment ring 220 serves to adjust anelectric field at a peripheral portion of the substrate W by covering alocation near a peripheral portion of a substrate W over a predeterminedwidth. Thus, an electric field is adjusted at a peripheral portion ofthe substrate W. Accordingly, an electric field produced between theanode 56 and the substrate W can be uniformized over the entire surfaceof the substrate W, including an edge portion of the substrate W, whichserves as an electrically receiving portion. Therefore, as shown in FIG.30, a metal film P having an enhanced within wafer uniformity can beformed on the surface of the substrate W, including the edge portion ofthe substrate.

[0151]FIG. 31 shows a plating apparatus 170 d according to yet anotherembodiment of the present invention. The plating apparatus 170 d has aplating solution injection type aditating mechanism 202, which is shownin FIG. 23, disposed between the anode 56 and the regulation plate 60 inthe anode side chamber 40 a, instead of the paddle-type agitatingmechanism 64 used in the plating apparatus shown in FIGS. 28 and 29.Specifically, in this example, a plating solution 10 fed by a pump 50 issupplied to the plating solution supply pipe 204 and injected from theplating solution injection nozzles 206 toward a plating solution passage200 a of the cylindrical member 200. Thus, the plating solution 10 isintroduced into the plating tank 186, overflows upper ends of overflowweirs 44, and is circulated. Other constructions are the same as thoseshown in FIGS. 28 and 29.

[0152] Thus, the plating solution injection type agitating mechanism 202is disposed in the anode side chamber 40 a, and the plating solution isinjected from the plating solution injection nozzles 206 toward theplating solution passage 200 a of the cylindrical member 200. Theplating solution can be supplied through the plating solution passage200 a to the substrate W held by the substrate holder 160 even if a gapG1 between an electric field adjustment ring 220 and the substrate Wheld by the substrate 160 is narrow.

[0153] As shown in FIGS. 32A and 32B, an insertion hole 60 b may beformed in the regulation plate 60, and a cylindrical member 200 havingan inside diameter D, a length L, a plating solution passage 200 ainside an inner circumferential surface thereof, and an electric fieldadjustment ring 220 attached to an end surface thereof may be insertedinto the insertion hole 60 b substantially in the same manner as shownin FIGS. 24A and 24B. Thus, the cylindrical member 200 may be held at apredetermined position along a longitudinal direction of the cylindricalmember 200.

[0154] As shown in FIGS. 33A and 33B, a large number of through-holes200 b having a size such as to prevent leakage of an electric field maybe formed in a circumferential wall of a cylindrical member 200 havingan electric field adjustment ring 220 attached to an end surface thereofsubstantially in the same manner as shown in FIGS. 25A and 25B. Thus,the plating solution 10 can pass through the through-holes 200 b formedin the circumferential wall of the cylindrical member 200 whilepreventing leakage of the electric field.

[0155] Further, as shown in FIGS. 34A and 34B, the electric fieldadjustment ring 220 may not be fixed to the end surface of thecylindrical member 200, but may be supported by a support 222 so as tohave a gap G2 between the front of the substrate W side end surface ofthe cylindrical member 200 and the substrate W. As with the gap G1between the electric field adjustment ring 220 and the substrate W, thegap G2 is generally set to be in a range of 0.5 to 30 mm, preferably 1to 15 mm, more preferably 1.5 to 6 mm. With the plating solution passage200 a thus formed, the cylindrical member 200 and the electric fieldadjustment ring 220 can be separated so as to offer a broader choice.

[0156] As shown in FIGS. 35A and 35B, a plating solution passage 224 ahaving a predetermined inside diameter D and a length L may be definedby an inner circumferential surface of a thick ring 224 having asufficient thickness, and an electric field adjustment ring 224 b havinga predetermined width A may be formed by a substrate side end surface ofthe thick ring 224. In this case, the number of parts can be reduced.

[0157] Although the aforementioned examples show that the presentinvention is applied to a so-called dipping type plating apparatus, thepresent invention is also applicable to a face-down type platingapparatus or a face-up type plating apparatus.

[0158]FIG. 36 shows an example in which the present invention is appliedto a face-down type plating apparatus. In this example, the followingstructures are added to a conventional plating apparatus shown in FIG.37. Specifically, a regulation plate 230 having a central hole 230 aformed therein is disposed at an upper position of the plating tank 12so as to separate the interior of the plating tank 12 into an anode sidechamber 12 a and a substrate side chamber 12 b. Further, a cylindricalmember 232 having an inside diameter equal to the diameter of thecentral hole 230 a and an inner circumferential surface forming aplating solution passage 232 a is concentrically attached to an uppersurface of the regulation plate 230 in a manner so as to project upward.With this arrangement, an electric field produced between the anode 16and a substrate W in the plating tank 12 can pass along the platingsolution passage 232 a, i.e. uniformly through the cylindrical member232 without leaking out of the cylindrical member 232. Accordingly,distortion and deviation of the electric field can be adjusted andcorrected so as to equalize a potential distribution over the entiresurface of the substrate W.

[0159] An electric field adjustment ring having an inside diameter equalto an inside diameter of the cylindrical member and a predeterminedwidth may concentrically be attached to an upper end surface of thecylindrical member so as to cover a location near a peripheral portionof the substrate W over a predetermined width. Thus, an electric fieldcan be adjusted at the peripheral portion of the substrate W.Accordingly, an electric field produced between the anode 56 and thesubstrate can be uniformized over the entire surface of the substrate,including an edge portion of the substrate, which serves as anelectrically receiving portion. Therefore, a metal film having anenhanced within wafer uniformity can be formed on the surface of thesubstrate, including the edge portion of the substrate.

1. A plating apparatus characterized by comprising: a plating tank forholding a plating solution; an anode disposed so as to be immersed inthe plating solution in said plating tank; a regulation plate disposedbetween said anode and a plating workpiece disposed so as to face saidanode; and a plating power supply for supply a current between saidanode and the plating workpiece to carry out plating, wherein saidregulation plate is disposed so as to separate the plating solution heldin said plating tank into a plating solution on said anode side and aplating solution on the plating workpiece side, and a through-hole grouphaving a large number of through-holes is formed in said regulationplate.
 2. The plating apparatus according to claim 1, characterized inthat said through-hole group is formed by a plurality of slit-likeelongated holes extending linearly in one direction or extending in anarc.
 3. The plating apparatus according to claim 1, characterized inthat said through-hole group is formed by a plurality of cross holesextending crosswise in vertical and horizontal directions.
 4. Theplating apparatus according to claim 1, characterized in that saidthrough-hole group is formed by a combination of a plurality of fineholes, a plurality of holes having different diameters, and slit-likeelongated holes.
 5. The plating apparatus according to claim 1,characterized in that said through-hole group is formed in saidregulation plate substantially over an entire area facing the platingworkpiece, and formed in an area substantially similar to a shape of theplating workpiece.
 6. The plating apparatus according to claim 1,characterized by comprising an agitating mechanism provided between theplating workpiece and said regulation plate for agitating the platingsolution held in said plating tank.
 7. The plating apparatus accordingto claim 6, characterized in that said agitating mechanism comprises apaddle-type agitating mechanism having a paddle which reciprocatesparallel to the plating workpiece.
 8. The plating apparatus according toclaim 1, characterized in that said anode and said regulation plate areprovided in a vertical direction.
 9. A plating apparatus characterizedby comprising: a plating tank for holding a plating solution; an anodedisposed so as to be immersed in the plating solution in said platingtank; a regulation plate disposed between said anode and a platingworkpiece disposed so as to face said anode; and a plating power supplyfor supply a current between said anode and the plating workpiece tocarry out plating, wherein said regulation plate is disposed so as toseparate the plating solution held in said plating tank into a platingsolution on said anode side and a plating solution on the platingworkpiece side, and a plating solution passage is formed in saidregulation plate for allowing an electric field to uniformly passtherethrough and allowing the plating solution to pass therethrough. 10.The plating apparatus according to claim 9, characterized in that alength of said plating solution passage is set to be in a range of 10 to90 mm.
 11. The plating apparatus according to claim 9, characterized inthat said plating solution passage is defined by an innercircumferential surface of a cylindrical member or a rectangular block.12. The plating apparatus according to claim 11, characterized in that alarge number of through-holes having a size such as to prevent leakageof an electric field are formed in a circumferential wall of saidcylindrical member.
 13. The plating apparatus according to claim 9,characterized by comprising an agitating mechanism provided in at leastone of a space between the plating workpiece and said regulation plateand a space between said anode and said regulation plate for agitatingthe plating solution held in said plating tank.
 14. The platingapparatus according to claim 13, characterized in that said agitatingmechanism comprises a paddle-type agitating mechanism having a paddlewhich reciprocates parallel to the plating workpiece.
 15. The platingapparatus according to claim 13, characterized in that said agitatingmechanism comprises a plating solution injection type agitatingmechanism having a plurality of plating solution injection nozzles forinjecting the plating solution toward the plating workpiece.
 16. Theplating apparatus according to claim 13, characterized in that saidplating solution passage is formed in said regulation plate integrallywith said regulation plate.
 17. A plating apparatus characterized bycomprising: a plating tank for holding a plating solution; an anodedisposed so as to be immersed in the plating solution in said platingtank; a regulation plate disposed between said anode and a platingworkpiece disposed so as to face said anode for separating the platingsolution held in said plating tank into a plating solution on said anodeside and a plating solution on the plating workpiece side, saidregulation plate having a plating solution passage for allowing anelectric field to uniformly pass therethrough and allowing the platingsolution to pass therethrough; a plating power supply for supply acurrent between said anode and the plating workpiece to carry outplating; and an electric field adjustment ring disposed at an end ofsaid plating solution passage on the plating workpiece side foradjusting an electric field at a peripheral portion of the platingworkpiece.
 18. The plating apparatus according to claim 17,characterized in that a width of said electric field adjustment ring isset to be in a range of 1 to 20 mm.
 19. The plating apparatus accordingto claim 17, characterized in that a gap between said electric fieldadjustment ring and the plating workpiece is set to be in a range of 0.5to 30 mm.
 20. The plating apparatus according to claim 17, characterizedin that said plating solution passage is defined by an innercircumferential surface of a cylindrical member, and said electric fieldadjustment ring is connected to an end of said cylindrical member on theplating workpiece side.
 21. The plating apparatus according to claim 20,characterized in that a large number of through-holes having a size suchas to prevent leakage of an electric field are formed in acircumferential wall of said cylindrical member.
 22. The platingapparatus according to claim 17, characterized in that said platingsolution passage is defined by an inner circumferential surface of acylindrical member, and said electric field adjustment ring is disposedat an end of said cylindrical member on the plating workpiece side so asto be separated from said cylindrical member.
 23. The plating apparatusaccording to claim 17, characterized in that said plating solutionpassage is defined by an inner circumferential surface of a cylindricalmember, and said electric field adjustment ring is formed on an endsurface of the plating workpiece side.
 24. The plating apparatusaccording to claim 17, characterized by comprising an agitatingmechanism provided in at least one of a space between the platingworkpiece and said regulation plate and a space between said anode andsaid regulation plate for agitating the plating solution held in saidplating tank.
 25. The plating apparatus according to claim 24,characterized in that said agitating mechanism comprises a paddle-typeagitating mechanism having a paddle which reciprocates parallel to theplating workpiece.
 26. The plating apparatus according to claim 24,characterized in that said agitating mechanism comprises a platingsolution injection type agitating mechanism having a plurality ofplating solution injection nozzles for injecting the plating solutiontoward the plating workpiece.